1. Field of the Invention
The present invention relates to a dispensing nozzle and cap. The invention also relates to an assembly comprising the nozzle or cap and to a container fitted with the nozzle and/or cap.
2. Brief Description of Related Technology
There have been provided many types of nozzles for dispensing a dispensable product. Caps which fit over the nozzle to close the nozzle off after use and for storage are also well known. The nozzles/caps may be employed in many end-use applications.
One problem which arises in certain instances is the removal of the cap from the nozzle. This occurs when the nozzle has been used to dispense product and product remains on the exterior of the nozzle when the dispensing action is complete. Replacement of the cap over the nozzle, often times then causes the cap also to be contaminated with the remaining product. This may in turn cause difficulty in subsequent removal of the cap from the nozzle. Product may for example cause the cap to be bonded to the nozzle and/or may otherwise interfere with the removal of the cap from the nozzle for example by fouling screw-threads etc.
Difficulty of removal of the cap from its position over-fitting the nozzle is undesirable, as a user of the product which is being dispensed, may find that they can no longer manually remove the cap from the nozzle, because the resistance to doing so by the product may be too great. If any tool is employed to assist a user in trying to remove a difficult-to-remove cap then the force applied to remove the cap can damage the nozzle and/or cap so that they no longer fit together in the required fashion. It is quite usual, in circumstances where a mechanical force is employed, to experience some form of material failure for example: shearing off the nozzle; breakage of the cap; or rupturing of the container for holding the product to be dispensed.
Attempts have been made to provide nozzle/cap arrangements which seek to minimise the circumstances in which material failure might occur, and to allow a user to remove the cap from its position over-fitting the nozzle with a minimum of force.
One known cap/nozzle assembly comprises a cap of the type having an elongate nozzle body having a base and a second dispensing end. A conduit defined in the nozzle body is provided for delivering product from the base to the dispensing end. The nozzle has three portions of different diameter. One portion of the nozzle is provided with external screw threads, which co-operate with internal reciprocal threads on the exterior of an over-fitting cap.
The over-fitting cap is of the type having a first closed end; a housing defining a second open end and with a rim about the open end. The cap is also provided with screwthreads, which co-operate with the external reciprocal threads on the exterior of the nozzle.
Both parts are typically made from very strong plastics material, so that they can withstand the quite substantial forces which may be applied, to try to remove the cap from its position over-fitting the nozzle. The screwthreads are arranged with a relatively low pitch so that the relative rotation of the cap and the nozzle is relatively easy for the user. The screwthreads are located at a position where they are spaced quite a distance from the dispensing end of the nozzle so that the risk of contamination with product is minimised. However even with such a construction the two parts become bonded and prove difficult to remove. Notwithstanding the use of stronger materials, material failure such as described above can occur in the event that relatively substantial mechanical force is applied.
Furthermore the costs of the materials which are used to make the nozzle/cap arrangement are substantial, given the need for strongly constructed components which is reflected in thicker walls etc. which in turn is achieved by utilising greater amounts of materials. In some earlier constructions a pin provided within the cap and arranged to penetrate the conduit of the nozzle was necessarily of metal construction. Another problem experienced with some prior art arrangements is that of spreading of the cap due to deformation of the cap due to forces applied to remove the cap from the nozzle. In such case the cap diameter misshapes spreading away from the nozzle.
It is thus desirable to provide a nozzle and cap arrangement which addresses the problem of difficulty in opening the cap when the arrangement is contaminated with product and also to reduce costs in the materials being employed, in particular by reducing the amounts of materials being employed, and also by reducing the assembly costs during manufacture.